The present invention relates generally to integrated circuit (IC) memory devices, and more specifically, to a low power sense amplifier for a static random access memory (SRAM) device.
Contemporary memory access circuits rely on differential sense amplifiers to read small signals generated by a selected memory cell from a memory device such as an SRAM. These sense amplifiers typically use transistors configured in a cross-coupled fashion to amplify a small voltage differential created by the cell. This cross-coupled configuration of transistors is used to tolerate variation in device threshold by relying on device matching of the transistors as opposed to the absolute threshold voltages of the transistors. As semiconductor device technology continues to evolve towards providing smaller device sizes and more devices per IC (and thus smaller voltages utilized within the circuits within the IC), there is an increase in local device mismatch caused by random variation, including random dopant fluctuation and line edge roughness. One approach that has been used to reduce mismatch between transistors is by increasing the area of the cross-coupled devices. However, an increase in the area of the cross-coupled devices increases switching current and leakage. Higher leakage also degrades performance of the SRAM. 